Libya attack graphically marks rise of fundamentalist Muslims

Still, in Libya there appears to be have been a mix of motives driving the consulate attack.

Journalists who visited the scene during the attacks told the BBC they heard frequent angry reference to the film.

Yet just hours earlier, Al Qaeda leader Ayman al-Zawahiri released a video to mark the 11th anniversary of the 9/11 attacks. He confirmed the death of a senior Libyan member of Al Qaeda, Abu Yahya al-Libi, in a US drone strike in Pakistan last June, and said: "His blood is calling, urging and inciting you to fight and kill the crusaders."

"I would argue that a great deal of planning went into the [Libya] attack, they fired multiple missiles into the consulate, they are well known for their anti-American views," says Mr. Gerges of the Salafist militant group that carried out the attack.

Anger could spread

Anger over the film expressed in Benghazi and Cairo could also spread to Afghanistan. The Taliban – removed from the Arab uprisings, but fighting US-led NATO forces, and sharing the theological roots of the most conservative Salafis – called on Afghans to fight such insults.